"Our government is extremely disappointed that the U.S. continues to uphold this protectionist policy (COOL), which the WTO has ruled to be unfair, and we call on the United States to abide by the WTO ruling," says Canadian Minister of International Trade Ed Fast and Canadian Minister of Agriculture Gerry Ritz.

The U.S. submitted changes to COOL late last month, just ahead of the May 23 deadline to comply with a WTO ruling that determined COOL policies negatively impacted trade.

Specifically, Mexico and Canada say the labeling rules, which allow the U.S. to list country of origin on certain agricultural products, are "technical barriers to trade."